I found this tree peony seedling in my patch today (out of Kamatanishiki, likely self pollinated, although I do have Feng Dan Bai in another bed in the general vicinity). It doesn't appear that the leaves are unhealthy and no other seedlings in that bed, or any other, have similar foliage. I looked up tree peony diseases and couldn't find anything that matched the look. What do you experts think? Does anyone know of any variegated-leaf peonies?

Interesting I wouldn't destroy it because we don't know what is going on. Is there anything else around that shows similar patters, any other plant? Hopefully, someone on this forum will have an idea.

I came across a research paper on viruses of ornamental plants a month ago. I've been planning to email the author re a violet with variegated leaves that showed up in my garden. I will mention your peony too.

"Look deep into nature, and then you will understand everything better."~Albert Einstein

Thanks for the link, Jasmin! I wish the photo was still available. Anyway, I definitely won't destroy my seedling --I actually did the opposite and gave it some composted manure and a tomato cage for a little more protection. Now it's just a waiting game, I guess!

You can still see the thumbnail image if you google "peony variegated leaves" and when you get results, click on the Images. The first picture of the first row is the picture of the peony with variegated leaves.

"Look deep into nature, and then you will understand everything better."~Albert Einstein